1. Field of the Invention
The present invention relates to inflatable structures, and more particularly, to a system and method for providing side impact and rollover protection in a vehicle from the roof rail to the belt line.
2. Background of the Invention
Inflatable structures are widely used to protect vehicle occupants during rapid vehicle deceleration, such as the deceleration encountered in a collision. Vehicle manufacturers place inflatable structures throughout vehicles in strategic locations where occupants can be expected to impact hard vehicle components. Generally, manufacturers may place inflatable structures above and/or below the dashboard on both the driver and passenger side, and along the sides of the vehicle at both the head level just below the roof rail, and the hip level, or xe2x80x9cbelt-linexe2x80x9d level, just above the door panel. The lower inflatable structures protect the leg, hip, and lower torso of the occupant, while the upper inflatable structures cushion the head and upper torso. For purposes of this specification, and as shown in FIG. 1, the belt line 100 is the bottom edge of the side window opening in an automobile door, while the roof rail 102 is the upper edge of the side window opening.
In a conventional installation, an inflatable structure is stowed in an uninflated state within a vehicle component, e.g., roof rail, as the dotted line 104 represents in FIG. 1.
The typical construction of an inflatable structure includes an inflatable chamber 106 with one cord or strap 108 attached at each end. The cords or straps (hereinafter referred to as xe2x80x9ccordsxe2x80x9d) attach the inflatable structure to anchor points 110 on the vehicle structure. Typically, these anchor points are statically mounted fasteners, e.g., M6 bolts. As used herein, statically mounted refers to an anchor that allows a cord to which it is attached to pivot around it, but not to move through it or around it.
Upon deployment, the inflatable structure inflates and emerges from its stowed location. The inflation fills the interior chamber of the inflatable structure, expands the walls of the inflatable structure, and reduces the overall length of the inflatable structure. The inflatable structure can be of any shape that substantially reduces in length when it inflates, such as a tubular or oval shape. As an example, inflatable tubular structures are described in U.S. Pat. No. 5,322,322 to Bark et al., which is assigned to the assignee of the present invention and is hereby incorporated by reference in its entirety. As another example, U.S. Pat. No. 5,788,270 to Hxc3x85land et al. describes another type of inflatable structure that reduces in length upon inflation.
The shorter axial length of a deployed inflatable structure pulls on the anchor points to which the inflatable structure is attached to produce substantial tension. This axial tension keeps the inflated inflatable structure in the desired deployed location, centered between the two anchor points. To provide side impact head protection for front and rear seat passengers, an inflatable structure is generally mounted to the upper portions of the A-pillar and the C-pillar of an automobile. FIG. 1 illustrates this typical prior art installation, with the inflatable structure attached to the A-pillar A and C-pillar C, and spanning the B-pillar B. Similarly, to provide side impact torso protection, an inflatable structure (not shown in FIG. 1) is attached to the lower portions of the A-pillar A and the C-pillar C of the vehicle.
As FIG. 1 illustrates, in the stowed position, the uninflated inflatable structure lies along a path 104 from its first anchor point 110, through the vehicle structure in which it is enclosed (e.g., roof rail 102), and to its second anchor point 110. In the deployed position, the inflatable structure extends along the shortest line connecting the two anchor points 110. Thus, the stowed length of the inflatable structure is greater than its deployed length. In addition, the closer the anchor points 110 are to belt line 100, the greater the stowed length is in proportion to the deployed length. Thus, a belt-line inflatable structure must reduce its length during deployment substantially more than an inflatable structure that is mounted at head level.
In addition, some vehicle geometries require belt-line inflatable structures to reduce their lengths even more. Vehicle platforms that have tall window openings greatly increase the proportion of stowed length to deployed length. For example, vehicles such as trucks, vans, and some sports-utility vehicles, have tall, narrow window openings that require a long stowed length up the pillars and around the roof rail, and a relatively short deployed length spanning the narrow window.
To provide adequate protection, an inflatable structure must develop considerable axial tension so that the inflatable structure maintains a rigid, impact-absorbing area that cushions an occupant""s body from the hard vehicle components. In comparison to head level inflatable structures, attaining this axial tension is a significant challenge for belt-line mounted inflatable structures because of the greater difference in length between the stowed and deployed positions. The practical result of this geometry is that belt-line mounted inflatable structure do not achieve the desired tension for maximum occupant protection. In fact, with some trucks and other vehicles with tall windows, the proportion of stowed length to deployed length is too great, acceptable tension is unattainable, and belt-line deployment is impossible.
Thus, there remains a need for an inflatable structure system that provides adequate tension for belt-line applications.
The present invention is a system and method for deploying a lower, or belt-line, inflatable structure with substantial axial tension. The system, referred to herein as an inflatable structure system, includes an inflatable structure serial assembly held on its ends by two static anchors. The serial assembly can be independent inflatable structures connected together, or one continuous inflatable structure. One or more dynamic anchors, mounted opposite the static anchors, restrains the serial assembly at an intermediate portion of the serial assembly such that the serial assembly has a first axis between the one static anchor and the one or more dynamic anchors and a second axis between the other static anchor and the one or more dynamic anchors. The one or more dynamic anchors allow the serial assembly to move axially along the first axis and the second axis, to equalize the axial tension of the serial assembly along the first and second axes.
In an embodiment of the present invention, as shown in FIG. 2a, the inflatable structure system includes an upper inflatable structure 200, a lower or belt-line inflatable structure 204, an upper static anchor 202, a lower or belt-line static anchor 208, and at least one dynamic anchor 205. In a further embodiment, the inflatable structure system also includes a shield (not shown in FIG. 2a) covering both inflatable structures.
The two static anchors 202 and 208 are mounted on a vehicle structure (or member) opposite to a vehicle structure (or member) on which the at least one dynamic anchor 205 is mounted. For example, as in the embodiment of FIG. 2a, dynamic anchor 205 could be on A-pillar A and the two static anchors 202 and 208 could be on the C-pillar C. Of course, anchors 202, 208, and 205 could be mounted on any pillars (e.g., including a B-pillar), members, or other structures of a vehicle, so long as anchors 202 and 208 oppose dynamic anchor 205. As another example, dynamic anchor 205 could be on C-pillar C, with static anchors 202 and 208 on A-pillar A. Of the two static anchors, upper static anchor 202 is closer to roof rail 212 than belt-line (or lower) static anchor 208.
Upper inflatable structure 200 is attached to upper static anchor 202 and to belt-line inflatable structure 204. Belt-line inflatable structure 204 is attached to belt-line static anchor 208. Upper inflatable structure 200 and belt-line inflatable structure 204 are connected to form a serial assembly from upper static anchor 202 to belt-line static anchor 208. The at least one dynamic anchor 205 restrains the serial assembly at an intermediate portion of the serial assembly, such that the serial assembly changes direction at the intermediate portion. In this example, the intermediate portion is the point at which upper inflatable structure 200 and belt-line inflatable structure 204 are connected. As shown in FIG. 2a, a joining cord 203 connects inflatable structures 200 and 204 and serves as the intermediate portion. In this manner, the inflatable structures are fixed between upper static anchor 202 and belt-line static anchor 208, but can travel back and forth in an axial direction along the path from upper static anchor 202 to at least one dynamic anchor 205 and to belt-line static anchor 208.
As used herein, a dynamic anchor refers to a device that takes two non-opposing forces that would be applied to two independent inflatable structures and makes the forces opposing, such that the forces are applied against each other and are substantially equal. In support of this definition, FIG. 2b illustrates two independent, deployed inflatable structures 250 and 251. Inflatable structure 250 is held by two anchors 253 and 254, which apply forces F1 and F2 on inflatable structure 250, respectively. Likewise, inflatable structure 251 is held by two anchors 255 and 256, which apply forces F3 and F4 on inflatable structure 251, respectively. Therefore, as shown, forces F2 and F4 are the non-opposing forces 257 that a dynamic anchor would make opposing.
FIG. 2c illustrates an exemplary dynamic anchor 260 that applies forces F2 and F4 against each other to create opposing forces 258. Dynamic anchor 260 creates opposing forces 258 by allowing a cord 259 that connects the two inflatable structures 250 and 251 to move through dynamic anchor 260 or slide around it. In this embodiment, dynamic anchor 260 could be a bushing mounted on a shaft attached to a vehicle structure.
As another example, FIG. 2d shows a dynamic anchor 261 that is a first-class lever. Inflatable structure 250 is attached to one side of lever 261, while inflatable structure 251 is attached to the other side. In between, the fulcrum 262 of lever 261 is pivotally attached so that lever 261 can rotate, or teeter-totter, as represented by the arrow 263. This teeter-totter action causes force F2 and force F4 to oppose each other (opposing forces 258).
In another embodiment of the present invention, a dynamic anchor could be more than one dynamic anchor. In another embodiment, the position of a dynamic anchor could also be adjustable.
Returning to FIG. 2a, the components of the present invention stow in a vehicle structure, e.g., roof rail 212. Upon deployment, belt-line inflatable structure 204 and upper inflatable structure 200 inflate and drop from the vehicle structure. The inflation expands the chamber walls of inflatable structures 200 and 204, reduces the overall length of inflatable structures 200 and 204, and pulls the cords taut. In pulling the cords, upper inflatable structure 200 approaches a position in line between upper static anchor 202 and the dynamic anchor 205 to which it is held. Similarly, belt-line inflatable structure 204 approaches a position in line between belt-line static anchor 208 and the dynamic anchor 205 to which it is held. If a shield is included in the inflatable structure system, the inflatable structures expand the shield as the inflatable structures inflate into their desired deployment locations.
As the lengths of upper inflatable structure 200 and belt-line inflatable structure 204 decrease and the tension on the cords increases, joining cord 203 (which is wrapped around the at least one dynamic anchor 205) slides around the at least one dynamic anchor 205. The at least one dynamic anchor 205 allows joining cord 203 to slide, but restricts both upper inflatable structure 200 and belt-line inflatable structure 204 with respect to their tensile direction. Because the cords of upper inflatable structure 200 and belt-line inflatable structure 204 are joined, the inflatable structures move in series. In this manner, axial tension substantially equalizes between the two inflatable structures, allowing upper inflatable structure 200 to compensate for the lower tension of belt-line inflatable structure 204. Therefore, the system provides a consistent acceptable tension across both of the inflatable structures and, if a shield is included, across the entire surface area of the shield.
Thus, the present invention provides an improved inflatable structure system that produces satisfactory axial tension for a belt-line inflatable structure. Improving the axial tension of the belt-line inflatable structure by coupling it with the upper inflatable structure increases the effective area of impact protection, extending it to the belt line of the vehicle.
Although the figures of this application illustrate embodiments of the present invention that use inflatable tubular structures, one of ordinary skill in the art would appreciate that the present invention is equally applicable to other inflatable structures as well. For this reason, and notwithstanding the particular benefits associated with using inflatable tubular structures, the systems and methods described herein should be considered broadly useful for any inflatable structure that substantially reduces in length when it inflates.
Accordingly, an object of the present invention is to provide impact protection and protection from partial ejection from the roof rail to the belt-line of a vehicle.
Another object of the present invention is to provide an inflatable structure system that contributes to the protection of a vehicle occupant""s torso.
Another object of the present invention is to provide a belt-line inflatable structure with adequate axial tension.
Another object of the present invention is to compensate for the reduced axial tension of one inflatable structure with the axial tension of another inflatable structure.
These and other objects of the present invention are described in greater detail in the detailed description of the invention, the appended drawings, and the attached claims.